You come to work one day, and your boss says you need to develop a real-time dashboard displaying some business defined KPI’s. You ask what KPI’s, and realize the nightmare begins as the data requested was modeled for OLTP. Not OLAP.
Oh, and I should have mentioned. Real-time means real time. Not 60 or 30 minutes.
For example, a user clicks save and someone’s dashboard KPI immediately increments by one.